Centralized traffic controlling system for railroads



w. K. HOWE 2,153,520

GENTRALIZED TRAFFIC CONTROLLING SYSTEM FOR RAILROADS v April 4, 1939.

Filed April 1, 1936 n m l BY 4/ ATTORNEY Patented Apr. 4, 1939 CENTRALIZED TRAFFIC CON'IRGLLING SYSTEM FOR RAILEOADS Winthrop K. Howe, Rochester, N. 12., assignor to General Railway Signal Company, Rochester, N. Y.

Application April 1, 1936, Serial No. 72,120

2 Claims.

This invention relates to centralized traific controlling systems for railroads, and more particularly pertains to a system of indicating the position and condition of a railway track switch to the central office operator.

One object of the present invention is to provide a single indicator on the control panel in the central oflice for advising the operator of the position and locked condition of a distant track switch, as well as advising the operator when such track switch is locked so as to prevent a control operation.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawing and in part pointed out as the description of the invention, progresses.

In describing the invention in detail reference will be made to the accompanying drawing which is a diagrammatic illustration of one embodiment of the present invention as applied to the control of traffic over a single railroad track switch.

Although the trafiic controlling system of the present invention may be applied to various track layouts involving conflicting routes and nonconfiicting routes as well as various other conditions encountered in interlocking practices, it has been specifically illustrated in the present embodiment as applied to a single track switch with its signals, which switch and signals are preferably associatedwith an automatic block system, of the type shown, such as for example, in the application of S. N. Wight, Ser. No. 120,423, filed July 3, 1926, now U. S. Patent 2,082,436, granted June 1, 1937, or associated with an interlocking system of the type shown for example in the a plication of S. N. Wight, Ser. No. 721,696, filed April 21, 1934, now U. S. Patent 2,121,846, granted 40 June 28, 1938.

With reference to the accompanying drawing, a railroad track switch TS is illustrated as connecting the rails 3 of a main track to the rails 4 of a diverging route or turnout track. This track switch TS is operated by a power driven switch machine SM, which may be of any suitable type, such for example, as disclosed in my Patent No. 1,466,903, dated September 4, 1923. This switch machine may also be provided with a dual control selector to permit hand operation of the track switch, as shown for example, in my Patent No. 1,952,573, dated April 5, 1932. i

The main track adjacent the track switch TS and a portion of the diverging track up to the fouling point comprises a detector track circuit of the closed circuit type with the usual track battery 5 and track relay T, which detector track circuit is insulated from the rest of the track layout by the usual insulatedjoints.

, Traific over the track switch TS in an east 5 bound direction is governed by the signals IA and GB on the main track and. onto the diverging track respectively; while signals 2A and 2B are provided for governing tr-afic in a west bound direction on the main track and off the diverging track respectively.

The track switch TS and the switch machine SM are preferably provided with point detector contacts (not shown) of some suitable type, such as disclosed for example in the patent to C. S. Bushnell, Patent No. 1,517,236, dated November 25, 1924. These point detector contacts are employed to energize a switch position relay WP of the usual polar neutral type with one polarity when the track switch TS is in an extreme nor- N mal locked position, and to energize it with the opposite polarity when the track switch TS is in an extreme reverse locked position, or to deenergize this relay WP whenever the track switch TS is unlocked or the switch machine SM is in 25 operation. Such control of the relay WP is well understood and is merely indicated by a dotted line extending from the relay WP to the track switch TS and the switch machine SM.

As the relay WP is usually located at the field station for the purpose of providing signal circuit selection, a repeater relay WPP is indicated in the office as directly repeating the relay WP, and is also a relay oi the polar neutral type. Although the control of the relay WPP may be ac- 5 complished in any one of several ways by the various line circuits extending from the control office to the field station, it is sufficient for an understanding of the present invention to know that the relay WPP directly repeats the relay WP, all of which may be accomplished by a simple direct wire circuit, but which control has been merely indicated by a dotted line because of its obvious operation.

A polar neutral relay W2 is governed from the I control office over a suitable polarized line circuit including line wire 25 and a common return line. The polar contact 5 (or other contacts if required), when operated to one or the other of their extreme positions serve to operate the switch machine SM to normal or extreme locked positions, as described in the patent to C. S. Bushnell, Patent No. 1,958,360, dated May 8, 1934.

The relay WZ is controlled over the line wire 25 by the switch machine control lever SML which has associated therewith a lock repeating relay LP having two windings which are differentially connected as indicated by the arrows located therein, and is of the slow release type for purposes hereinafter pointed out.

The switch machine lever SML together with a signal control lever SGL and a lock indicator LK are associated with a miniature track diagram indicated as having a miniature track switch point is which is operated to the last locked position of the track switch TS by suitable electro-magnetic means controlled by contact 23 of relay WPP.

A flashing relay FL of the slow acting neutral type has been illustrated as associated with the indicator LK for reasons to be described hereinafter.

The signal control lever SGL controls suitable signal relays IBG, IAG, ZAG and ZBG through suitable circuit selections on the relay WP (or correspondence repeater relays not shown) as well as back contacts of the lock relay L, when desired. All of this control has been indicated by a dotted line, but it is to be understood that such control as disclosed in the Patent No. 2,009,187, dated July 23, 1935, granted to R. M. Phinney, may be incorporated herein without departing from the scope of the present invention. These signal control relays G (with suitable preceding signal designations) are also controlled in accordance with trafiic conditions, all of which has been omitted for the sake of simplicity.

When all of the signals are at stop, the relays G are deenergized closing a circuit for a signal at stop relay M from through a circuit including back contact 1 of relay IBG, back contact 8 of relay IAG, back contact 9 of relay ZAG, back contact ID of relay 213G, windings of relay M, to

The lock relay L is normally energized, while the signals are at stop and the detector track section is unoccupied, by a circuit closed from through a circuit including front contact ll of relay M, front contact l2 of relay T, windings of relay L, to It is to be understood that suitable approach locking may be applied to the control of the relay L and also various other adjuncts in connection with looking a track switch may be suitably applied as shown for example in the above mentioned Patent No. 2,009,187, dated July 23, 1935.

Instead of showing the battery sources at the central office and at the field station, suitable symbols have been employed. Symbols and have been employed to indicate the positive and negative terminals of a suitable source or sources of direct current, and the circuits with which these symbols are employed always have current flowing in the same direction. Similarly, symbols (B+), (B) and (CN) have been employed to illustrate the opposite terminals and mid-tap of a center tapped battery, and the circuits with which such symbols are employed may have current flowing in one direction or the other depending upon whether (B) or (3+) is employed with the center or midtap (CN).

It is believed that further description of the present invention will be best understood by setting forth the characteristic features and functions of the system in typical operations thereof.

Operation Normal conditions.-With the detector track section associated with the track switch TS unoccupied by a train; and with the control levers SML and SGL in the positions shown, the various devices, relays and circuits assume positions and conditions of energization, as illustrated.

The relay T is, of course, normally energized.

The lock relay L is normally energized by a circuit pointed out above.

The relay M is normally energized by a circuit pointed out above.

The normal energizing circuit for the relay W2 is closed from the positive terminal of the battery (B-|-) through a circuit including the upper winding of relay LP, contact I3 of the lever SML in a normal position, line wire 25, front contact M of relay L, windings of relay WZ, through the common return wire, to (CN). This energization of the relay WZ of course actuates the polar contacts to the right hand polar position and picks up the neutral contacts of the relay. This circuit also causes the neutral contacts of the lock repeating relay LP to be picked up.

Control of the track switch-Let us assume that the operator moves the switch machine control lever SML to a reverse dotted line position. The contacts of the lever SML are preferably of the quick acting type, so that the polarity is reversed upon the control circuit before the relay LP (which is but slightly slow acting) can become deenergized and drop its contacts, In other words, the reverse control circuit is closed including contact l3 of lever SML in its dotted line position to apply (3-) to the line circuit including line wire 25. As the current now flows through the relay WZ in the opposite direction, its polar contacts are operated to left hand dotted line positions and its neutral contacts are picked up, although it is of course, understood that the neutral contacts momentarily assume dropped away positions during the reversal of the current in the windings of the relay WZ. The contacts of the relay LP remain picked up.

With the lever SML in a reverse dotted line position, an out-of-correspondence circuit is closed for the lock indicator LK from through a circuit including the winding of the flashing relay FL, back contact l5 of relay FL, polar contact l6 of relay WPP in a right hand position, lever contact I! in a dotted line reverse position, front contact I8 of relay LP, indicator lamp LK, to The current, which flows in this circuit to illuminate the indicator LK, is intermittently interrupted due to the picking up and dropping of the contact l5 of the flashing relay FL. This operation of relay FL is readily apparent as back contact I5 controls the breaking and closure of the circuit of such relay. In other words, the indicator LK is intermittently illuminated or flashed during the time that the track switch TS is out of correspondence with the switch machine lever SML, due to the vibratory action of relay FL.

The relay WZ through its polar contact 6 controlsthe switch machine SM so as to operate the track switch TS to its reverse position. During the operation of the track switch TS, the relays WP and WPP are of course deenergized, and during this deenergized condition of the switch position repeating relays, the back contact I9 of relay WPP shunts the contacts l6 and I! so that the indicator LK is continually flashed irrespective of the operation of the lever SML.

Upon the completion of the operation of the track switch TS to the extreme reverse locked position, the polar contacts of the relays WP and Ill) WPP are operated to the left and their neutral contacts are picked up. With contact [6 of relay WPP in a left hand dotted line position, the circuit through the contact ll of lever SML is opened and the picking up of the neutral contact IQ of such relay also opens the shunt circuit for the correspondence contacts, all of which is efiective to cause the indicator LK tobe unilluminated.

The miniature track switch point is is controlled by contact 23 of the relay WPP to its reverse position. In brief, the operator is advised by the position of the miniature track switch point ts of the actual position of the track switch TS while the flashing of the indicator LK, which is illustrated as located beneath the miniature track switch point ts, advises the operator that the lever SML is out of correspondence with the position of the track switch as indicated by the miniature track switch point ts, and upon the unillumination of the indicator LK, he knows that the track switch TS has completed its operation.

When the lever SML is returned to its normal position, it is apparent that the contact 20 of lever SML closes a circuit with contact H5 in a reverse position to initiate the flashing of the in.- dicator lamp LK and to continue it until correspondence is restored by the return of the lever SML or until the track switch has operated into correspondence therewith. While the track switch is in midstroke the back contact i9 is closed to shunt the correspondence contacts of the lever SML and relay WPP, as noted above.

The return of the track switch TS to a normal position of course is repeated by the relays WP and. WPP, so that the miniature track switch point is is returned to its normal position through the control of contact 23 of relay WPP, and upon the establishment of correspondence between the lever SML and the track switch TS, the indicator LK becomes unilluminated advising the operator of such correspondence.

It might be noted in this connection, that should the track switch TS be manually operated by a trainman, the relays WP and WPP would be deenergized and the back contact I!) would close the circuit for intermittently energizing the indicator lamp LK to advise the operator of such condition. The operator recognizes the condition of unlocking of the track switch, because he can readily see that lever SML and miniature track switch is are in corresponding positions.

During the control of the relay WZ, the relay LP remains picked up, but, when a signal is cleared by the operation of the lever SGL toone position or the other for establishing the proper direction of traflic, and clearing the proper signal, the relay M is deenergized which opens contact ll deenergizing the relay L.

More specifically, the operation of the lever SGL to the right energizes either the relay IAG or the relay IBG depending upon whether the track switch TS is in normal or reverse positions respectively; while the operation of the lever SGL to the left energizes either the relay 2AG or the relay ZBG depending upon whether the track switch TS is in normal or reverse positions respectively. Such control is believed tobe well understood in the art and has not been shown in detail.

The closure of back contact I 4 of relay L com.- pletes a local stick circuit for. the relay WZ to maintain it energized while the track switch is locked against control. This stick circuit for the normal position of the relay WZ is closed from (13+), through a circuit including polar contact 2| in a right hand position, front contact 22 of relay WZ, back contact M of relay L, windings of relay WZ, to: (ON). The reverse stick circuit for relay WZ is closed from (B-), through polar contact 2| in a left hand position, front contact 22 of relay WZ, back contact M of relay L, windings of relay WZ, to (CN).

The opening of front contact l4 deenergizes the line circuit including the relay LP in the central office so that the contacts of relay LP drop away. The closure of back contact it of relay LP con.- nects the indicator LK, to through the resistor B so that the indicator LK is steadily illuminated. This resistor R, is of substantially the same resistance value as the flashing relay FL, so as to maintain substantially the same voltage on the indicator LK under both steady illumination and intermittent illumination.

This steady illumination of the indicator LK warns the operator that the track switch cannot be operated and that he should not operate the lever SML at such time. signals to stop of course closes the circuit for the lock relay L at front contact ll of relay M and the relay LP responds causing the indicator LK to be unilluminated providing of course that the lever SML is in correspondence with the position of the track switch TS.

It might be mentioned at this point, that the system of control shown in the embodiment of the present invention, illustrates direct control of the track switch, but it is to be understood that the lever lock equivalent such as shown in the above mentioned Patent No. 2,009,187, where a stick contact is employed on the lock repeating relay LP and a correspondence contact is employed on the relay WPP, may also be used in the system in accordance with the present invention. When such an arrangement is employed, the relay LP remains deenergized upon the picking up of the contact Id of the relay L if the lever SML is out of correspondence with the position of the track switch TS as indicated by the relay WPP. This would cause the indicator LK to remain steadily illuminated upon the picking up of the relay L, which condition would continue until correspondence was again established. Such cor respondence would not be automatically established by the response of the track switch, but would be set up by the manual return of the lever SML into correspondence with theswitch TS.

It is also to be understood that the contacts I3, l1 and 2!] on the lever SML may be located on a switch control relay Z employed in the entranceexit type of interlocking control in application Ser. No. 721,696, filed April 21, 1934, previously mentioned, so that such relay is operated by the joint operation of two control buttons one at each end of the route to be set up. The resulting control of the indicator lamp LK is not changed in such a system but provides the same indication as herein described. This is true even, though the lever lock equivalent may also-be employed with such switch controlling relay Z, as disclosed in the above mentioned application 721,696, filed April 21, 1934.

Although the flashing relay FL has been shown as associated only with the indicator LK, it is to be understood that it may be associated with other similar indicators for other track switches. Also, any suitable means may be employed to The return of the track replace the flashing relay FL, such as a motor driven contactor or a steadily operated flashing relay for supplying intermittent energy to a bus to which a plurality of indicators LK may be connected as shown in the present disclosure, all of which is to be understood as included within the scope of the present invention.

Thus, a system for the control of an indicator is provided which indicates to the operator by intermittent illumination of such indicator that the switch control means and the track switch are out of correspondence either due tothe operation of the switch control means or due to the hand operation of the track switch in the field; while the steady illumination of such indicator displays to the operator the information that the track switch is locked against manual control. Such indication is provided in combination with a miniature track switch point which shows the last locked position of the switch.

Having described a trafiic controlling system employing a single indicator to display the information required with regard to a track switch a as one embodiment of the present invention, it

is desired to be understood that this form is selected to facilitate in the disclosure of the present invention, rather than to limit the number of forms which it may assume; and, it is tobe further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from'the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:

1. In a control system, in combination, a local control station and a distant spaced location, a power operated track switch at the distant location, a switch control lever at the station for operating contacts at the station for controlling the power operation of the switch over a control circuit, a lock relay for at times preventing control of the switch by the lever, a polar neutral switch position repeating relay at the station, 1

an indication circuit for the polar relay separate from the control circuit, a single indicator lamp at the station, means for steadily energizing the lamp when the lock relay is effective to prevent power control of the switch, means for energizing the lamp intermittently through a circuit ineluding in series, polar contacts of the switch repeating relay, and contacts of the lever when the lever and the track switch are out of correspondence; and means for flashing the lamp through the same circuit except that a neutral contact on the switch repeating relay shunts the lever contacts and the polar contacts of the switch repeating relay.

2. In a control system, in combination, a local control station and a distant spaced location, a power operated track switch at the distant location, a switch control lever at the station for operating contacts at the station for controlling the power operation of the switch, a lock relay, for at times preventing control of the switch by the lever, a polar neutral switch position repeating relay at the station, a single indicator lamp at the station, means for steadily energizing the lamp when the lock relay is effective to prevent power control of the switch, means for energizing the lamp intermittently through a circuit including in series, the winding of the flashing relay, a back point of the flashing relay, polar contacts of the switch repeating relay, and contacts of the lever when the lever and the track switch are out of correspondence; and means for flashing the lamp through the same circuit except that a '1 W'INTHROP K. HOWE. 

